This AREA application seeks to establish a new collaboration among three investigators at the University of Rhode Island with complementary expertise in marine microbial natural products chemistry, deep ocean microbiology, and antibiotics research. This collaboration will capitalize upon expeditions of the Integrated Ocean Drilling Program (IODP) to provide access to the seafloor of the world ocean. Our proposal seeks to leverage the millions of dollars of federal funds that support IODP expeditions by isolating novel microorganisms from remote, deep ocean environments for drug discovery. The initial focus for these studies will be on diverse bacteria cultivated from sediment cores retrieved within the South Pacific Gyre, an enormous mid-ocean zone that has yet to be accessed by drug discovery investigations. AIM 1 will create a novel collection of genetically diverse bacteria isolated from ocean sediments acquired at abyssal (>2000 m) depths. The microbes will be isolated using methods tailored to life adapted to low nutrient and high-pressure environments. Natural products chemistry (AIM 2) will then link the biosynthetic capabilities of these organisms with pharmacological evaluation of their secondary metabolites. Antibiotic testing will be conducted on pure microbial metabolites and semi-purified fractions from culture supernatants. The focus of this testing (AIM 3) will be growth inhibition of both ATCC and clinical strains of multiple drug resistant Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Thus, this project will focus on finding antibiotics against the most problematic clinical pathogens. Pure molecules will be quantitatively tested for bacterial growth inhibition and reduction of biofilm formation using proven and cutting edge methods. For example, compounds that prevent biofilm formation will be tested in an intravascular catheter model. These tests will determine if antibiotic agents can prevent biofilms from forming in catheters, a problematic source of infections in hospitals. All compounds will be additionally tested for cytotoxicity and sufficient quantities will be submitted to the NIH Molecular Libraries Small Molecule Repository for more comprehensive biomedical evaluation. The proposed collaboration will enhance the competitiveness of health-related research at the University of Rhode Island and will promote cross-disciplinary training of both undergraduate and graduate students in sciences related to drug discovery. Human Health Relevance: The long-term goal of the project is the discovery of new antimicrobial agents useful in the treatment of drug-resistant bacterial infections. Our ability to treat infectious disease is increasingly compromised by the emergence of drug-resistant strains of pathogenic bacteria. For example, more than 60% of staph infections in intensive care units are resistant to at least one medicine commonly used to treat these infections. Antibiotic drug discovery is not keeping pace with rising resistance. This project will extend our search for new antibiotics to include novel molecules produced by microbes from the most remote deep ocean environments, a highly promising but mostly unknown resource. PUBLIC HEALTH RELEVANCE: This project will investigate previously inaccessible microbial biodiversity in the deep ocean as novel resources for biomedical discovery. A specific project goal is the discovery of potent new antibiotics to combat drug resistant pathogens.